Layers of failure cited in fatal copter accident

NTSB finds altered documents, lack of safety oversight

by Joan Lowy - Dec. 8, 2010 12:00 AMAssociated Press

WASHINGTON - A firefighting helicopter crash that killed nine people two years ago was caused by deceptions on the part of the company that leased the aircraft to the U.S. Forest Service and a lack of federal safety oversight, the National Transportation Safety Board determined Tuesday.

Carson Helicopters of Grants Pass, Ore., intentionally altered documents to exaggerate the helicopter's performance capabilities in order to win a Forest Service contract, the board said.

But the Federal Aviation Administration and the Forest Service missed several opportunities to uncover those problems, the board said.

"This accident had more to do with Carson's actions than the oversight entities' inactions," NTSB chairman Deborah Hersman said. "But the FAA and the Forest Service didn't hold up their end of the deal to oversee Carson's actions."

The accident points to a larger problem of a lack of safety oversight of non-military aircraft operations by federal, state and local government agencies, board members said. The FAA has said it doesn't have the authority to oversee the aircraft operations of other agencies.

NTSB has alerted the Department of Transportation's Inspector General that Carson's actions may merit a criminal investigation, Hersman said.

The board's investigation showed the Sikorsky S-61N helicopter weighed 19,008 pounds when pilots tried to take off from a rugged mountaintop clearing near Weaverville, Calif., on Aug. 5, 2008. But the maximum weight to lift off at full power with no margin to spare was 18,445 pounds, they said. If Forest Service guidelines, which include a safety margin, had been followed, the weight shouldn't have exceeded 15,840 pounds, investigators said.

Carson also provided its pilots with procedures for estimating liftoff weight that eroded safety margins, the board said.

Carson has surrendered its FAA certificate, the agency said in a statement released after the board meeting. The certificate is the equivalent of an operating license. The FAA is also working on clarifying its policy on oversight of government aircraft, the statement said.

The Forest Service said in a statement that it is committed to learn from such tragedies and has "aggressively pursued opportunities to improve its operations from the onset of this accident."

Carson Helicopters issued a statement saying it believes the cause of the crash was a loss of power to the No. 2 engine due to the failure of a fuel-control unit while the helicopter was taking off. The company added that their own inquiry uncovered a history of problems with the fuel-control unit on the Sikorsky S-61N helicopter.

However, NTSB said it didn't find that problem in this accident.

The helicopter was airborne less than a minute when the rotor began to slow, it clipped a tree and fell into the forest. It was carrying firefighters from the front lines of a stubborn wildfire in the Trinity Alps Wilderness.

Seven firefighters, the pilot and a Forest Service safety inspector were killed. The co-pilot and three firefighters were injured.